theorize

verb

the·​o·​rize ˈthē-ə-ˌrīz 

ˈthir-ˌīz

theorized; theorizing

intransitive verb

: to form a theory : speculate

transitive verb

1

: to form a theory about

2

: to propose as a theory

theorization

ˌthē-ə-rə-ˈzā-shən 

ˌthir-ə-

noun

theorizer noun

Examples of theorize in a Sentence

Many scientists have theorized about the possibility of life on other planets.

Recent Examples on the Web

There’s no need to theorize about what happened here because the obvious answer is Bret Easton Ellis signed off on the first two episodes and then abandoned the adaptation. — Louis Peitzman, Vulture, 13 Aug. 2026

One feature worth further research, the authors noted, are the gaps or clumps in stellar streams that scientists theorize develop when small concentrations of dark matter pass through them. — Taylor Nicioli, CNN Money, 13 Aug. 2026

Nagiewicz also theorized that the sharks could have been dumped offshore by fishermen. — Charna Flam, PEOPLE, 13 Aug. 2026

Other experts have theorized the dramatic swings may have more to do with the state tests themselves than with student performance. — Cayla Bamberger, New York Daily News, 13 Aug. 2026

Word History

First Known Use

1644, in the meaning defined at transitive sense 1

Rhymes for theorize

• advise
• applies
• apprise
• arise
• assize
• baptize
• belies
• bitwise
• capsize
• chastise
• chordwise
• clockwise

Kids Definition

theorize

verb

the·​o·​rize ˈthē-ə-ˌrīz 

theorized; theorizing

: to form a theory : speculate

theorizer noun